Telescoping electrode protector



May 29, 1923. 1,456,894

G. M. LITTLE TELES COPING ELECTRODE PROTECTOR Filed May 24, 1921 WITNESSES' INVENTOR 777.7 I GeggeM [(ff/e.

Patented May 29, 1923.

. UNITED STATES; PATEN,T'OFFI CE GEORGE M. LITTLE, or PITTSBURGH, PENNSYLVANIA, AssIGNon o WEs Tr oHoUs ELECTRIC & MANUFACTURING COMPANY, A CORPORATION or P N SY VANIA.

TELESCOPING ELECTRODE PROTECTORf Application filed May 24,

To. all whom it may concern: 1

. Be it known that I, Gnonon M. LITTLE, .a citizen of the United States, and a-resldent of Pittsburgh. in thecounty of Allegheny and State of Pennsylvanimhave invented a i new. and useful Improvement in Telescoping means of a resilient compression means and a carbonaceous electrode which extends through one of the walls of the furnace. 1

I have found that the portion of the e'leo-.

trode just outside of'the furnace wall operates at a temperature sufficiently high to per. mit' of an oxidizing effect of the air upon the electrode. I

In practicing my invention, I provide a mass of granular carbonaceous materialsurrounding that portion of the electrode extending between a water-cooled contact ter minal located'at the outerend thereof and the outer face of the furnace and maintain the said mass in its proper operative position by means of a two-part telescoping container. One part of this container is secured to the outer surface of the furnace wall and the other part is secured to the metallic contact terminal. As the electrode has limited -longitudinal movement relatively to the furnace wall through which it passes, the two parts of the container are permitted to move relatively to each other while maintaining the granular mass in its proper operative position. s

In the single sheet of drawings:

Figure l is a view, in vertical cross-section, of an electric-resistance furnace comprising the device embodying my invention, and

Fig. 2 is a view, in lateral cross-section, on the line IIII of Fig. 1.

An electric furnace 1 comprises a metallic framework or casing 2 and. suitable support- 1921. Serial No. 472,096.

ing members 3. .-Outer wallsv atcomprise a plurality of bricks iorblocks of a suitable heat-insulatingmaterial; Inner Walls 5 comprise a plurality of bricksor blocks of a suitable-high-temperattire-resisting material. The walls 5 are suitably spaced apartto form a furnace chamberfi of any suitable or desired contour and dimensions.

As a furnace of the above indicated character is intended to'be employed to heat metallic articles, an opening 7 is provided in one of the walls of the furnace near the bottom of the chamber to-permit of'intro! ducing and removing such articles.

A heating element 8 forthe furnace com-'- prises a-plurality of flat carbonaceous members substantially of the character described in the herein'before 'mentionedapplication. The heating element or resistor 8 is compressed by means of an elongated carbonaceous electrode 9 extending through a suitable opening in one of.v the furnace walls and engaging, at its inner end, a graphite end plate 10. a r I A resilient compression means. comprises an adjustable screw 11: and a helical spring 12, the inner end of which operativelyfengages the outer end of the electrode 9, an insulating member 13 being interposed bee tween the outer end of the electrodeandthe helical spring to suitably insulate these mem here from each other. vWhile I have illustrated a specific embodiment of the resilient compression means, I .do not desiieto be limited to this device as this is illustrated schematically only and any suitable or desired resilient compression means may be employed.

A water-cooled metallic contact terminal terminal 14 must necessarily be located some distance away from the furnace wall. This, of course, exposes a portion of the length of the electrode 9 and, as the temperature of this exposed portion of-the electrode may become so high as to permit the same to be oxidized by the air surrounding it, protecting means are provided. These means comprise a thin metal plate 16 of substantially U-shape secured against an insulating. member 17' mounted on the out-side of the furnace casing 2 and a second plate 18 also of substantially U-shape, secured to an insulating member 19 which is bolted against the inner surface of the contact terminal 14. The member 18 secured to the contact terminal lei is placed inside of, and engaging, the plate 16 over a portion of its length, the members 17, 16, 18 and 19 forming a container for a mass 20 of granular carbonaceous material placed therein to surround the elect-rode 9 over a portion of its length.

, As. the temperature of the electrode 9 at that portion of its length located inside walls 1 and 5 is relatively high, I provide means comprising a well or'hopper 21 and a mass 22 of granular carbonaceous material surrounding that part of the electrode lying in the walls 1 and 5, to prevent the oxidizing effect of any air tending to flow along the electrode through the furnace chamber or of any air in which may leak in through the walls 4 and 5 between the individual bricks or blocks. This device is more fully described and claimed in my copending application, Serial No. ll-72,093, filed May 24, 1921.

It may be noted that the telescoping container comprising the metallic members 16 and 18 forms a relatively simple means for maintaining the mass 20 of granular carbonaceous material in its proper operative posit-ion around the electrode while permitting movement of one member relatively to the other member or part, as may be required by the movement of the electrode relatively to the furnace well through which it passes.

Various modifications may be made in the device embodying my invention without departing from the spirit and scope thereof and I desire that only such limitations shall be placed thereon as are imposed by the prior art or are specifically set forth in the appended claims.

I claim as my invention:

1. An electric furnace comprising a plurality of furnace walls enclosing a furnace chamber, a resistor in said chamber, a carbonaceous electrode extending through one of said walls for conducting current to and from said resistor and having limited longitudinal movement relatively to said Wall, a water-cooled terminal mounted on said electrode at its outer end, granular oxidizable material surrounding said electrode between said wall and said terminal and a two part telescoping container for said granular material, one part being secured to said Wall and the other part being located against said terminal.

2An electric furnace comprising a plurality of furnace walls enclosing a furnace chamber, a resistor in said chamber, a carbonaceous electrode extending through one of'said walls for conducting current to and from said resistor and having limited longitudinal movement relatively to said wall, a water-cooled terminal mounted on said electrode at its outer end, granular oxidizable material surrounding said electrode between said wall and said terminal and means for retaining said granular material in its operative position around said electrode irrespective of the movements of said elec trode and said contact terminal relatively to said wall and a two-part telescoping container for said granular material, one part being secured to said wall and the other part being located against said terminal.

In testimony whereof, I have hereunto subscribed my name this 18th day of May, 1921.

GEORGE M. LITTLE. 

